For understanding how to have a personal relationship with one's gods I'd suggest "Devoted To You" by Judy Harrow.
In terms of magical practice and spellwork you might want to try:
"Spells and How They Work" by Janet and Stewart Farrar
"Before You Cast a Spell" by Carl McColman
"The Veil's Edge" by Willow Polson
"Modern Magick" by Donald Michael Kraig
"Real Magic" by Isaac Bonewits.